What is Arc?
Circle built a blockchain where the dollar is the gas and the validators are banks. This page says what it is, who runs it and what Circle has committed to, using only Circle's own sources. Nothing here is a recommendation.
Arc is a sovereign, EVM-compatible Layer 1 blockchain built by Circle, the issuer of USDC. It is not an Ethereum rollup. Its gas token is USDC, so every fee is denominated in dollars and there is no volatile native coin to hold for gas. Blocks target 0.5 seconds with deterministic finality, the block gas limit is 30 million, and validation at launch is done by a permissioned set that Circle has named: Circle itself plus BlackRock, DTCC, Galaxy, Global Payments, ICE, Mastercard, MoneyGram, SBI Group, Standard Chartered, Sumitomo and Visa. Anyone will be able to deploy contracts and transact once public mainnet opens on 16 September 2026.
Circle describes Arc as open, programmable blockchain infrastructure for production financial applications: stablecoin payments, foreign exchange between stablecoins, tokenised real-world assets, capital markets, and transactions initiated by software agents. The pitch is that a bank's compliance team can sign off on a chain where fees are predictable, finality is sub-second, gas is a regulated dollar instrument, and the validators are institutions they already know.
Two design choices follow from that. Compliance hooks and privacy features are opt-in at the application level, so an institutional app can gate its users while a permissionless app next door does not. And the network launches with optional post-quantum wallet signatures, with a stated roadmap towards fuller quantum resistance over the following years.
- Chain ID
- 5042
- Testnet chain ID
- 5042002
- Gas token
- USDC
- Target block time
- 500 ms
- Block gas limit
- 30,000,000
- Validators in genesis config
- 11
- Predeployed system contracts
- 275
- CCTP domain
- 26
Read live on the terminal from circlefin/arc-node. The genesis is dated 12 May 2026 and mainnet has run since then behind a closed RPC. The USDC system contract sits at 0x3600000000000000000000000000000000000000. Of the 275 predeployed contracts, 19 are working contracts and the rest reserve address space.
Circle has not published a document titled "why not Base", so what follows is inference from its public filings and announcements, labelled as such. Under the Coinbase and Circle arrangement, a large share of the interest earned on USDC reserves goes to Coinbase, and Base's sequencer revenue is Coinbase's. On Arc, every transaction is denominated in USDC and the fee flows through infrastructure Circle operates. Circle's revenue is almost entirely reserve interest, which falls with rates; a chain adds fee income and a coordination token. And institutions such as BlackRock, DTCC and Visa have agreed to validate Arc, which is not something they would do on an exchange's chain.
The comparison set is other issuers and payment companies building settlement layers: Stripe with Tempo, Tether with Plasma and Stable, Robinhood with Robinhood Chain. Arc is Circle's answer to the same question.
USDC is freezable by Circle on every chain it exists on. On Arc it is also the gas. That means Circle does not need to touch consensus to stop a wallet: freezing its USDC leaves it unable to pay for any transaction at all. Separately, the genesis includes a protocol-level denylist, so compliance is enforced by the chain itself as well as by the USDC contract. The blacklister, pauser and master minter of the USDC contract are set to zero in the published config; because the public repository is a sync of a private one, that may not reflect the live chain, and the genesis watch shows it as a reading, not a signal.
- Arc, Circle's official site
- Arc documentation: key features
- Arc documentation: system overview
- Arc public mainnet launches 16 September 2026, Arc House, 6 August 2026
- circlefin/arc-node mainnet genesis and config - chain ID, block time, gas limit, validators, USDC system contract
Chain facts on this page come only from Circle. Where a figure is the site's own reading, the terminal card it comes from is linked. Definitions are on the method page.